Despite an important role in differentiating the causes of LVH (1), standard echocardiography techniques are not able to distinguish the etiology in a large number of cases, especially at the early phase of the diseases when the typical features are not necessarily present. Assessment of myocardial deformation or strain using 2D speckel-tracking has emerged as a potential means to differentiate hypertrophic cardiomyopathy from hypertensive heart disease, athlete’s heart, and also cardiac amyloidosis (2-5).
The authors used an interesting method in order to evaluate the real impact of Two-Dimensional Speckle-Tracking Longitudinal Strain in that setting. They include only patients with moderate LVH (14±1mm), without obvious ECG abnormalities in favor of a given diagnosis. The assessment of the diagnosis (HCM or CA or HHD) was performed by 20 echocardiographic readers unaware of the cases. During a first session they classified the documents without data on Two-Dimensional Speckle-Tracking Longitudinal Strain but with detailed conventional echocardiography and also tissue Doppler evaluation at lateral and medial mitral annulus. During a second session they classified the patients with the help of Two-Dimensional Speckle-Tracking Longitudinal Strain. The readers also evaluated the confidence with correctness of the diagnosis according to a semi quantitative scale. The readers previously had a teaching session about the interpretation of Longitudinal Strain (LS) in the context of LVH and the representation of typical pattern of strain polar maps (eye bull representation of LS): relative apical sparing of LS with reduced LS at the basal and middle levels of LV (cardiac amyloidosis), reduced LS at the site of greatest hypertrophy (hypertrophic cardiomyopathy).
However the study demonstrates that the addition of a strain polar map to standard echocardiographic parameters in this cohort significantly improves reader concordance, diagnostic accuracy, and confidence in making the correct diagnosis. The typical representation of strain polar map is an easy tool that should help us to appropriately diagnose the etiology of LVH and therefore will facilitate the appropriate management of the patients.
The authors used an interesting method in order to evaluate the real impact of Two-Dimensional Speckle-Tracking Longitudinal Strain in that setting. They include only patients with moderate LVH (14±1mm), without obvious ECG abnormalities in favor of a given diagnosis. The assessment of the diagnosis (HCM or CA or HHD) was performed by 20 echocardiographic readers unaware of the cases. During a first session they classified the documents without data on Two-Dimensional Speckle-Tracking Longitudinal Strain but with detailed conventional echocardiography and also tissue Doppler evaluation at lateral and medial mitral annulus. During a second session they classified the patients with the help of Two-Dimensional Speckle-Tracking Longitudinal Strain. The readers also evaluated the confidence with correctness of the diagnosis according to a semi quantitative scale. The readers previously had a teaching session about the interpretation of Longitudinal Strain (LS) in the context of LVH and the representation of typical pattern of strain polar maps (eye bull representation of LS): relative apical sparing of LS with reduced LS at the basal and middle levels of LV (cardiac amyloidosis), reduced LS at the site of greatest hypertrophy (hypertrophic cardiomyopathy).
Conclusion:
A limitation of the study is the small sample size of the population (3 groups of 8 patients). A second point to underline is that no single echographic parameter will provide the magic key but requires to be interpreted in the context of various components of diagnostic work-up (including personal history and symptoms, ECG, basic biology etc) as emphazised by a recent position paper of the WG (1).However the study demonstrates that the addition of a strain polar map to standard echocardiographic parameters in this cohort significantly improves reader concordance, diagnostic accuracy, and confidence in making the correct diagnosis. The typical representation of strain polar map is an easy tool that should help us to appropriately diagnose the etiology of LVH and therefore will facilitate the appropriate management of the patients.
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